Laboratory and Field Studies of Photocatalytic NOₓ and O₃ Removal by Coatings on Concrete

This project involved thorough testing of titanium dioxide (TiO₂)-containing commercial photocatalytic coatings applied to portland cement concrete for highway applications, focusing on the use of these coatings as an abatement method for atmospheric nitrogen oxide (NOₓ) and ozone (O₃). The study consisted of four parts: laboratory chamber testing; outdoor exposure studies; modeling; and field application. Full-factorial experiments in laboratory chambers designed to examine the impact of variables such as temperature, relative humidity, time, and pollutant concentrations on NOₓ and O₃ removal by the coatings demonstrated that a commercial stucco was the best performer of the four original materials tested. After one and two years of outdoor, roadside exposure, the NOₓ removal capacity of the stucco decreased significantly, but could be improved by soap and water washing. A Comprehensive Air Quality Model with extensions (CAMx) for the Houston-Galveston-Brazoria and Dallas-Fort Worth areas showed the potential of the stucco to reduce average ozone concentrations if large areas of highway structures are coated. Testing at a field site in north Austin, however, showed no conclusive difference between air quality in areas with coated and uncoated highway barriers. Therefore, while photocatalytic concrete coatings have promise for improving air quality, the data from this project suggest that such improvements may not be significant enough to be measured experimentally in common roadway configurations such as the site tested for this study.

• Record URL:
  http://library.ctr.utexas.edu/ctr-publications/0-6636-1.pdf
• 
• Record URL:
  https://rosap.ntl.bts.gov/view/dot/32130
• Supplemental Notes:
  • Project Title: Photocatalytic NOₓ/HRVOC/O₃ Removal in Transportation Applications. Report Date: December 2016; Published March 2017.
• Corporate Authors:

  University of Texas, Austin

  Center for Transportation Research, 1616 Guadalupe Street
  Austin, TX  United States  78701-1255

  Texas Department of Transportation

  Research and Technology Implementation Office, P.O. Box 5080
  Austin, TX  United States  78763-5080

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Crain, Neil
  • Juenger, Maria
  • Cros, Clement
  • Terpeluk, Alexandra
  • Burris, Lisa
  • McDonald-Buller, Elena
  • Sullivan, David
  • Kimura, Yosuke
  • Spinhirne, Jarett
  • Rung, Michael
• Publication Date: 2017-3

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Technical Report
• Features: Appendices; Figures; Maps; Photos; References; Tables;
• Pagination: 345p

Subject/Index Terms

• TRT Terms: Air quality; Coatings; Field tests; Laboratory tests; Nitrogen oxides; Ozone; Portland cement concrete; Stucco
• Uncontrolled Terms: Air quality models; Concrete barriers; Photocatalysis; Titanium dioxide
• Geographic Terms: Austin (Texas); Brazoria (Texas); Dallas (Texas); Fort Worth (Texas); Galveston (Texas); Houston (Texas)
• Subject Areas: Environment; Highways; Materials;

Filing Info

• Accession Number: 01634626
• Record Type: Publication
• Report/Paper Numbers: FHWA/TX-17/0-6636-1, Report No. 0-6636-1
• Contract Numbers: 0-6636
• Files: NTL, TRIS, ATRI, USDOT, STATEDOT
• Created Date: May 10 2017 1:07PM